Tsuga (Endl.) Carr.

Tsuga is a small genus of ca. 10 species, native in the northern hemisphere (but none in Belgium). Two North American species are more or less widely cultivated for timber production or as ornamentals: Tsuga canadensis and T. heterophylla. Both were recently recorded as escapes from cultivation in Belgium.

Leaf margins in Tsuga are often minutely spinulose. However, spinules are usually very inconspicuous and unevenly distributed and almost lack in young leaves of saplings. This character should therefore be checked on adult leaves of the supposed parental plants. In saplings of Tsuga leaves are markedly bicoloured: white stomatal bands on the abaxial surface are very prominent and contrast with the shiny green adaxial surface.

  • Leaves gradually narrowed at apex, abaxially with few lines of stomatal bands (5-6) === 1. Tsuga canadensis
  • Leaves parallel-sided and very abruptly narrowed at apex, abaxially with 7-8 lines of stomatal bands === 2. T. heterophylla


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Taxonomic name: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith